<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<style>
    header {
        width: 1200px;
        height: 200px;
        background-color: antiquewhite;
        margin: 0 auto;
    }
</style>
<body>
    <header>
        header模块
    </header>
    <main>
        main finish!!!
    </main>
    123121231
</body>
</html>